JPH08143704A - Vinyl chloride resin composition - Google Patents

Abstract

PURPOSE: To obtain a nontoxic vinyl chloride resin composition having good heat stability by mixing a vinyl chloride resin with a zinc stabilizer and a polyhydric alcohol stabilization aid having a low content of unreacted pentaerythrotol. CONSTITUTION: This method for preparting the polyhydric alcohol stabilization aid consists of mixing a dibasic acid (e.g. adipic acid) with 3-7mol, per mol of its anhydride (e.g. phthalic anydride), pentaerythritol, subjecting the resultant mixture to a dehydrative condensation reaction at 150-230 deg.C to remove (n-2) to (n) mol equivalent or below water when a dibasic acid is used or remove (n-2) to (n) mol equivalent or below water when the anhydride of a dibasic acid is used. The method of preparing the vinyl chloride resin composition consists of mixing 100 pts.wt. vinyl chloride resin with 0.1-10 pts.wt. zinc stabilizer such as a Ca-zinc and/or a Ba/zinc stabilizer (e.g. a metal soap in which the fatty acid moiety is a stearic acid, and the metal moiety contains Ca and Zinc) and 0.1-10 pts.wt. polyhydric alcohol stabilization aid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride resin composition having good thermal stability, and more particularly to a polyhydric alcohol stabilizer for vinyl chloride.

[0002]

BACKGROUND OF THE INVENTION Since vinyl chloride resins are inexpensive and have excellent physical properties, they are used in all fields including water pipes, building materials, electric wire coating materials, daily necessities, furniture, toys and medical infusion chaves. Since conventional vinyl chloride resins are easily degraded and decomposed by heat or light rays such as sunlight,
In order to prevent this, stabilizers such as lead-based, cadmium-based, and tin-based stabilizers have been added. However, recently, from the standpoint of environmental protection, lead-based, cadmium-based, and other heavy metal stabilizers, which are toxic, have been shunned and regulated.

As a means for solving these problems, non-toxic or low-toxic zinc-based stabilizers such as calcium-zinc based, barium-zinc based, and magnesium-zinc based stabilizers are being used. However, a vinyl chloride resin composition containing a zinc stabilizer produces zinc chloride once deterioration and decomposition start, and this zinc chloride causes a so-called zinc burning phenomenon that further accelerates deterioration of the vinyl chloride resin. In order to prevent this, it is well known that a polyhydric alcohol-based stabilizing aid is used in combination. As the polyhydric alcohol-based stabilizing aid, polyhydric alcohols such as pentaerythritol, dipentaerythritol, and tripentaerythritol are said to be effective, but in reality, these polyhydric alcohols have high melting points and Since the compatibility with the resin is poor, the thermal stability effect becomes insufficient and the transparency is deteriorated. Therefore, many methods of partially esterifying with a carboxylic acid to be used have been proposed.

For example, JP-A-55-69639, JP-B-57-61289 and JP-B-61-47866 disclose pentaerythritol and polypentaerythritol obtained by dehydration condensation of pentaerythritol by partial esterification with various carboxylic acids. Stabilizers for containing resins are disclosed. However, the molar ratio in the reaction of pentaerythritol and carboxylic acid in the above is about 1: 1 to 3:
It has been known that the content of the hydroxyl group in the molecule of the resulting reaction product is not sufficient in terms of practical stability effect. Therefore, when the inventors of the present application re-test the above-mentioned examples, the pentaerythritol dehydration condensate contains unreacted pentaerythritol in an amount of 30 to 40%, and tends to be colored brown as the dehydration condensation is further performed. It has been found. Further, it was found that 20 to 30% of unreacted pentaerythritol having a low molecular weight and high sublimability remained in the reaction product obtained by esterification with 1 mol of adipic acid based on 2 mol of the dehydrated condensate.

In fact, when a dehydration condensate containing a large amount of unreacted pentaerythritol is blended with a hard vinyl chloride resin, there is a problem in workability due to sublimation during processing, contamination of a processing machine, and a blending composition. There have been problems such as transparency of products and deterioration of impact resistance. In this respect, it has been difficult to say that conventionally known reaction products of pentaerythritol and its derivatives with various carboxylic acids have sufficient performance as a stabilizer. Further, the partial esterified product of dipentaerythritol and adipic acid has excellent impact resistance and thermal stability, but has a high melting point and a problem of dispersibility, resulting in a problem of transparency thereof. . That is, when a zinc-based stabilizer is blended in a vinyl chloride-based resin composition, finely ground dipentaerythritol conventionally used as a stabilizing aid or a partial esterification product of dipentaerythritol and adipic acid is used as a main component. Addition of various polyhydric alcohol-based stabilizing aids causes some problems in terms of their thermal stability effect, transparency of the compound, workability during compounding, etc., and satisfies all of these problems. There has been a long-felt need for a polyhydric alcohol-based stabilizing aid that can be used.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyhydric alcohol-based stabilizing aid having a low content of unreacted pentaerythritol, which is used in combination with a vinyl chloride resin in combination with a zinc-based stabilizer, and has physical properties. It is to obtain a good vinyl chloride resin composition.

[0007]

[Means for Solving the Problems] Pentaerythritol or its derivative and a proper molar ratio when reacting with a carboxylic acid, dehydration reaction conditions, control method of dehydration end point, composition in reaction product, etc. are examined in detail. I went to
1. When a polyhydric alcohol-based stabilizing aid containing pentaerythritol in an amount of more than 10 wt% is blended with a vinyl chloride resin, pentaerythritol is sublimated during processing of the vinyl chloride resin composition, depending on the blending amount. It is feared that the processing machine may be contaminated and the vinyl chloride-based resin composition product may be roughened, so that the content of pentaerythritol in the polyhydric alcohol-based stabilizer is 10 w.
t% or less is essential, and 2. In the synthesis of polyhydric alcohol-based stabilizing aids, pentaerythritol is reacted with a dibasic acid such as adipic acid or phthalic acid in a large excess to adjust the dehydration amount during the reaction. 2. An excellent stabilizing aid having a pentaerythritol content of 10 wt% or less in the alcohol-based stabilizer can be obtained, and It has been found that when a vinyl chloride resin composition is produced using it, workability is improved and the performance of the obtained composition is excellent.

That is, in the present invention, 3 mol or more and 7 mol or less of pentaerythritol is dehydrated and condensed in the presence of a catalyst with respect to 1 mol of a dibasic acid or an anhydride thereof, and n-1 mol in the case of a dibasic acid. In the case of an anhydride of a dibasic acid, n-2 molar equivalents or more and n
It is a polyhydric alcohol compound obtained by dehydrating water in a molar equivalent or less. The polyhydric alcohol compound obtained by the above reaction has a pentaerythritol content of 10% by weight or less. Further, in the present invention, a zinc-based stabilizer such as a calcium-zinc-based or barium-zinc-based stabilizer is used in an amount of 0.1 to 10 relative to 100 parts by weight of the vinyl chloride resin.
A vinyl chloride resin composition, characterized in that 0.1 to 10 parts by weight of the polyhydric alcohol-based reaction product is blended.

The dibasic acid used in the synthesis of the vinyl chloride resin composition used in the present invention includes adipic acid, succinic acid,
Very common dibasic acids such as maleic acid, malonic acid, phthalic acid, isophthalic acid, and terephthalic acid may be used. With monocarboxylic acids, it is difficult to obtain a higher hydroxyl group content by reaction with polyhydric alcohols, and with carboxylic acids with 3 or more basic acids, reaction with polyhydric alcohols easily gels, so the reaction end point Is difficult to manage. In addition, in the present invention, the above-mentioned dibasic acid anhydride, that is, phthalic anhydride, succinic anhydride, maleic anhydride, malonic anhydride, or the like can be used as a raw material. The dibasic acids and pentaerythritol, which are the raw materials of the present invention, may be in any form such as powder and flakes because they react in a molten state.

Examples of the acid catalyst used in the present invention include phosphoric acid, sulfuric acid, p-toluenesulfonic acid, sulfamic acid and the like, and these may be used alone or in combination. If the addition amount of the acid catalyst is 0.05 wt% or less, the reaction rate is slow, and if it is 5 wt% or more, the reaction rate does not further increase, and 0.05 to 5 wt% is sufficient.

In order to synthesize the polyhydric alcohol-based stabilizing aid of the present invention, pentaerythritol and dibasic acid are added to
It suffices to add an acid catalyst and obtain a predetermined dehydration amount at 150 to 230 ° C. When the reaction temperature is lower than 150 ° C., the reaction rate is slow, and when the temperature is higher than 230 ° C., a dehydration condensation mixture of pentaerythritol itself is liable to be generated, which causes coloring, and is preferably 180 to 225 ° C. The predetermined dehydration amount is
The molar ratio of pentaerythritol and dibasic acid is n: 1 (n:
When 3 ≦ n ≦ 7), n−1 molar equivalent or more and n + 1 molar equivalent or less. If the dehydration amount is more than n + 1 molar equivalents, the reaction proceeds too much, and the reaction solution gels. If the dehydration amount is less than n-1 molar equivalent, the unreacted pentaerythritol content will be higher than 10 Wt%. Therefore, the optimum dehydration amount is n-1 molar equivalent or more, n +
It is 1 molar equivalent or less. For example, in the reaction between 6 mol of pentaerythritol and 1 mol of adipic acid, the predetermined dehydration amount is 5 mol or more and 7 mol or less.

When the above-mentioned dibasic acid anhydride is used as the raw material in the present invention, the synthesis conditions are exactly the same as those when the dibasic acid is used, and pentaerythritol and the dibasic acid anhydride are used. Acid catalyst is added to the product, 150-230 ℃
It suffices to obtain a predetermined amount of dehydration. The predetermined dehydration amount is such that the molar ratio of pentaerythritol and the anhydride of dibasic acid is n: 1.
When (n is 3 ≦ n ≦ 7), it is not less than n−2 molar equivalent and not more than n molar equivalent. If the amount of dehydration is greater than n molar equivalents, the reaction proceeds too much and the reaction solution gels.
If the dehydration amount is less than n-2 molar equivalents, the unreacted pentaerythritol content will be higher than 10 Wt%. Therefore, the optimum dehydration amount is n-2 molar equivalents or more and n molar equivalents or less. For example, in the reaction between 6 mol of pentaerythritol and 1 mol of phthalic anhydride, the predetermined dehydration amount is 4 mol or more and 6 mol or less. Further, in the present invention,
There is no problem in mixing a plurality of dibasic acids and their anhydrides as raw materials, and a mixture of dibasic acids and anhydrides may be used. In that case, the dehydration amount that determines the reaction end point can be easily obtained by calculation from the molar ratio of the mixture.

In the present invention, it is desirable to increase the molar ratio of pentaerythritol to dibasic acid as much as possible in order to increase the content of hydroxyl groups in the molecule. In order to obtain a predetermined dehydration amount, it is necessary to perform a dehydration reaction for a long time, and as a result, the coloration becomes conspicuous with the progress of the reaction, and at a stage where the predetermined dehydration amount is obtained, the degree of coloring cannot be practically endured. Become.
Further, it has been found that when the molar ratio is less than 3, the reaction liquid tends to gel and the hydroxyl group content in the reaction product decreases, so that the effect of improving thermal stability cannot be expected when blended with a vinyl chloride resin. . Therefore, 3 to 7 is desirable to obtain the optimum molar ratio.

The above dehydration condensation reaction consists of an esterification reaction and an etherification reaction, and the compound obtained by the reaction is dipentaerythritol in which pentaerythritol is ether-bonded between molecules or further condensed, tripentaerythritol or tetrapentaerythritol. It is a compound in which the acid used in the reaction is ester-bonded to the hydroxyl group of linear or branched polypentaerythritol such as erythritol. Moreover, the obtained compound is a white crystal.

Further, in the reaction, the melting point of the polyhydric alcohol-based stabilizing aid is adjusted and the content of unreacted pentaerythritol is lowered, so that esterification or reaction with a small amount of other carboxylic acid may occur immediately before the reaction is completed. After the completion, 30 wt% or less of dipentaerythritol may be added and mixed together. In that case, regardless of the kind of the carboxylic acid, a monocarboxylic acid, a dicarboxylic acid, a carboxylic acid having 3 or more basic acids, and a mixture thereof can be used. However, in order to secure the hydroxyl group content, the addition amount should be suppressed to an amount at which the unreacted pentaerythritol and the carboxylic acid of the n-basic acid react at a molar ratio of n: 1.

The transparency of the vinyl chloride resin composition containing the polyhydric alcohol stabilizing aid is related to the melting point of the stabilizing aid and the processing temperature during compounding. That is, the melting point of the polyhydric alcohol-based stabilizing aid is preferably 140 to 180 ° C., and if the melting point is lower than 140 ° C., the melting point is too low, and there is a problem in production such as pulverization.
The dispersibility during processing is poor, and the transparency of the resulting resin composition is also poor. Therefore, the polyhydric alcohol-based stabilizing aid can arbitrarily select the kind of the basic dibasic acid so that the melting point thereof is in the range of 140 to 180 ° C., and for that purpose, pentaerythritol and The melting point can be adjusted by arbitrarily selecting the molar ratio of the basic acid within the range of 3: 1 to 7: 1.

The vinyl chloride resin used in the present invention may be a homopolymer of vinyl chloride or vinylidene chloride, a copolymer with ethylene, vinyl acetate, acryl or the like, or a blend of these polymers. The degree of polymerization or the size of the particles does not matter. The zinc-based stabilizer used in the present invention includes fatty acids such as stearic acid, ricinoleic acid,
Of metal soaps such as palmitic acid, octylic acid, benzoic acid, salicylic acid, etc., the metal part is used in combination such as sodium and zinc, calcium and zinc, magnesium and zinc, barium and zinc, or a commercially available zinc-based product. It is a complex stabilizer. The form of the stabilizer may be liquid, powder or the like.

The vinyl chloride resin composition of the present invention may be a soft system containing a plasticizer depending on the purpose of use of the composition. In that case, the compounding amount is 100% vinyl chloride resin.
The plasticizer is 0 to 150 parts by weight with respect to parts by weight. Examples of the plasticizer include phthalic acid esters such as dioctyl phthalate and diisodecyl phthalate, aliphatic dibasic acid esters such as dioctyl adipate and dioctyl azelate, tricresyl phosphate, trioctyl phosphate and the like, and epoxidized macromolecules. Soybean oil, paraffin chloride,
Other plasticizers may be used alone or in combination of two or more. Furthermore, if necessary, other additives may be blended in required amounts. Examples thereof include fillers such as calcium carbonate and aluminum hydroxide, flame retardants such as antimony oxide, colorants, antioxidants and stabilizers other than zinc-based stabilizers.

[0019]

[Example] With thermometer, stirrer, distillate trap device 1
Add adipic acid 14 to a 000 ml four-neck separable flask.
6 g (1 mol), 816 g (6 mol) of pentaerythritol and 1.4 g of paratoluenesulfonic acid were charged and heated, and an esterification reaction and an etherification reaction were carried out at 160 to 225 ° C. with stirring. By-product water is distilled off as the reaction progresses,
The reaction was stopped when the amount of distillate reached 90 g (5 mol). During this time, it was about 3 hours. Then, the reaction solution was poured into a vat, cooled to room temperature and then pulverized to obtain a white powder. This is Example 1.

Similarly, the dibasic acid and pentaerythritol are subjected to the esterification reaction and the etherification reaction at various molar ratios, and the reaction is stopped at various distillate amounts. It was crushed in the same manner as above to obtain various stabilizing aids.
(Examples 2 to 6, Comparative Examples 1 to 6)

The various stabilizing aids thus obtained were silylated with a silylating agent and then subjected to gas chromatography analysis to examine the contents of pentaerythritol, dipentaerythritol and tripentaerythritol. Further, 2 g of each stabilizing aid was sampled in a sublimation tube and immersed in an oil bath at 180 to 200 ° C. for 3 hours to measure the sublimation rate. The reaction conditions, results, and the above results are shown in Table 1.

[0022]

[Table 1]

Next, vinyl chloride resin (Geon 103E)
P) 100 g, dioctyl phthalate 50 g, calcium stearate 1 g, zinc stearate 1 g, and various stabilizing aids 1 g were mixed for 5 minutes with a 160 ° C. kneading roll (6 inches manufactured by Toyo Seiki Co., Ltd.). Thickness about 0.
A 5 mm sheet was obtained. This obtained sheet is
It was placed in a gear oven at ℃ and the heating time and the degree of coloration of the sheet were observed to judge the thermal stability. Also, the sheet obtained above is pressed by a press machine at 160 ° C. to a thickness of 3 mm.
After molding, the appearance such as transparency was visually observed. As various stabilizing aids, in addition to the substances of Examples and Comparative Examples, pentaerythritol, dipentaerythritol, tripentaerythritol, and Prelenizer ST-210 (manufactured by Ajinomoto Co., Inc.) were used for evaluation. Table 2 shows the results.

[0024]

[Table 2]

[0025]

As described above, a predetermined amount of water is obtained by the esterification and etherification reaction in the presence of the pentaerythritol of the present invention, a dibasic acid (molar ratio 3: 1 to 7: 1) and a suitable catalyst. The reaction product removed by-product has excellent thermal stability effect,
Since the melting point is close to the processing temperature, the dispersibility is good and there is almost no sublimation property during processing, when blended with the vinyl chloride resin composition, the vinyl chloride resin composition has good stability without impairing the appearance such as rough skin. Can be obtained and can be used for all purposes.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C08L 27/06 KGY // C07B 61/00 300

Claims (3)

[Claims] 1. A dibasic acid or 1 mol of its anhydride,
Dehydration condensation of 3 mol or more and 7 mol or less of pentaerythritol is carried out in the presence of an acid catalyst, and in the case of a dibasic acid, water of n-1 mol equivalent or more and n + 1 mol equivalent or less is dehydrated to dihydrate the dibasic acid anhydride. In this case, a polyhydric alcohol-based compound is obtained by dehydrating n-2 molar equivalents or more and n molar equivalents or less of water. 2. The content of pentaerythritol is 10% by weight.
It is the following, The polyhydric alcohol type compound of Claim 1 characterized by the following. 3. A zinc-based stabilizer such as a calcium-zinc-based or / and barium-zinc-based stabilizer is used in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the vinyl chloride-based resin. A vinyl chloride resin composition comprising 0.1 to 10 parts by weight of a polyhydric alcohol compound.